Means for regulating the tension of diaphragms of sound-producing instruments.



No. 695,883. Patented Mar. l8, I902.

J, F. LUSDO'M B. MEANS FOR REGULATING THE TENSION 0F DIAPHRAGMS [IF-SOUND PRODUCING INSTRUMENTS.

(Application filed May 16. 1901.) (No Model.)

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UNITED STATES PATENT OFFICE.

JOHN F. LUSOOMB, OF BOSTON, MASSACHUSETTS.

MEANS FOR REGULATING THE TENSION 0F DIAP HRAGMS OF SOUND-PRODUCING INSTRUMENTS.

SEEGRLFLEGATION forming part of Letters Patent No. 695,883, dated March 18, 1902.

Application filed May 16, 1.901.

To all whom it may concern:

Be it known that 1, JOHN F. LUSCOMB, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful improvements in Means for Regulating the Tension of Diaphragms of Sound- Producing Instruments; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, and to the letters of reference marked thereon.

The present invention has for its object to provide means for regulating the tension of the diaphragm of sound recording, reproducing, and transmitting instruments, such as phoncgraphs, gramophones, graphophones, and similar instruments where a reproducerdiaphragm is employed; and it consists in the means substantially as shown in the drawings and hereinafter described and claimed.

Figure 1 of thedrawings is a sectional elc vation of a reproducer-hcad embodying my invention; Fig. 2, a plan view of the compressor-ring; Fig. 3, a sectional elevation of the usual clamping-plate with tubular extension, showing the presser-ring formed upon the under side of the plate in place of being independent thereof.

In the accompanying drawings, A represents the usual frame, to which the reproducer-diaphragm B is connected through the medium of the plate or disk 0 and the usual screw-ring l), the reproducer-lever E and its connections being of the ordinary construction.

The several parts comprising the reproducer-head, as above described, are of the ordinary construction and is one of many forms of heads that may be used to illustrate the application of my invention thereto, the diaphragm being of any suitable material, either metallic, animal, or vegetable, although 1 prefer to use vellum or similar material.

With relation to the reproducer-diaphragm I find it necessary that some means should be provided. by which the tension thereof may be controlled and regulated, so that all blasting and harsh tones may be obviated and a more perfect action of the diaphragm secured. To regulate or adjust the tension of the dia- Serial No. 60,440. (No model.)

phragm, there is provided a ring F, which I term a pressure-ring, that is adapted to bear down upon the face of the diaphragm, and by pressure thereon the tension of said diaphragm will be regulated, the pressure of the ring being secured by the screw-ring 1) upon the disk O, thereby increasing the eX- cellency of the tone reproduction and removing all scratching and blasting heretofore existing. The pressure ring or device F can be brought with more or less pressure upon the diaphragm to suit any record by simply tightening or loosening the screw-ring D, thus increasing or decreasing the vibrations as circumstances require.

In place of having the pressure-ring independent, as shown in Figs. 1 and 2 of the drawings, the ring maybe formed with or integral with the disk or plate O, as shown in Fig. 3 of the drawings.

The diaphragm B is held between two flat clamping-rings G H, and said rings, with the diaphragm,are independent of and removable from the reproducer-head, the lower one of the rings resting upon the flange l of the frame A. The diaphragm, with its two clamping-rings, being independent of the reproducer-head may be readily removed and re placed by a new one or maybe used with any other form of head, as found desirable. The disk or plate C has a circumferential shoulder J, which extends slightly below the under side of the disk or plate to form a stop in limiting the downward movement thereof.

As will be seen in Fig. 1, the ring F bears on the diaphragm inside the clamping-rings, and the ring is of such height as to prevent contact of the disk O with the clamping-ring next adjacent, and the ring D bears on the disk at a point out of the plane of the ring F, so that the pressure of the ring D is not ditly on the ring F. By this arrangement 4 ts I have obtained better results and ate all harshness and secure a nicety of adjustment.

Having now fully described my invention, what Iclaim as new, and desire to secure by Letters Patent, is-

1. in a sound reproducing, recording or transmitting instrument, a suitable frame, a reproducer-diaphragm secured between rings at its outer edge, said rings being rcmovab y supported in the frame, a'pressure-ring of less diameter than the outer ring and held within the same and supported upon the diaphragm and of greater thickness than said rings, a disk or plate above the pressure-ring to give pressure thereto, and said disk engaging the pressure-ring out of the plane of rings, and a screw-ring engaging the screw-threads of the frame and adapted to force the disk or plate against the pressure-ring, the said pressurering being retained between the upper ring and the said plate, all substantially as shown and described. I

2. In a sound recording, reproducing or transmitting instrument, a suitable frame, a reproducer-diaphragm, removable rings between which the diaphragm is held, an independent pressure-ring bearing on the diaphragm inside said rings and of greater thickof two witnesses.

JOHN F. LUSCOMB. Witnesses:

W. A. GREAVES, JOSEPH P. SILSBY. 

